Significance of highly phosphorylated insulin-like growth factor binding protein-1 and cervical length for prediction of preterm delivery in twin pregnancies

Table 1 Characteristics of the twin pregnancy populations recruited in the study

Characteristic
Maternal age (yr)	28.35 ± 4.84 (21-38)
Gravidity (times)	1.66 ± 0.35 (1-3)
Parity (times)	0.14 ± 0.03 (0-1)
Types of conception, n (%)
Spontaneous conception	250 (98.43)
Medical intervention	4 (1.57)
Gestational age (wk)	26.54 ± 3.24 (24-34)
Pregnancy complications, n (%)
Gestational diabetes	114 (44.88)
Gestational hypertension	36 (14.17)
Thyroid dysfunction	56 (22.05)
Other complications (e.g., placenta, amniotic fluid and baby positions in womb)	48 (18.90)